On Tue, May 13, 2008 at 1:30 AM, Krishna Chandra Prajapati <[EMAIL PROTECTED]> wrote: > Hi all, > > Below is the user_delivery table structure. > > CREATE TABLE `user_delivery` ( > `user_id` decimal(22,0) NOT NULL default '0', > `delivery_id` decimal(22,0) NOT NULL default '0', > `send_to_regulator` char(1) default NULL, > PRIMARY KEY (`user_id`), > KEY `user_delivery_comp1` (`user_id`,`delivery_id`), > CONSTRAINT `fk_user_delivery` FOREIGN KEY (`user_id`) REFERENCES > `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION > ) ENGINE=InnoDB DEFAULT CHARSET=latin1; > > According to me user_delivery_comp1 index can be dropped and new index can > be created on delivery_id column. I would to know that the changes will work > or not. Yours suggestion regarding this table structure. > > Thanks, > -- > Krishna Chandra Prajapati >
Define work. The effect should be something like: Queries that have where clauses for delivery_id but not user_id would be able to use an index. Queries that have where clauses for delivery_id and user_id might not be able to use as much of an index. Depending on your version of mysql merge index may apply, but I am not knowledge enough to comment of the performance differences between the two. I would assume a composite index when available would generally be more ideal. -- Rob Wultsch [EMAIL PROTECTED] wultsch (aim) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
